Pulpal and periodontal diseases are bacterial infections which result in local connective tissue and bone destruction. The microorganisms which have been implicated as pathogens in these diseases are primarily gram negative anaerobes, which include Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Campylobacter recta (Dzink, J. L., et al., J. Clin. Periodontol. 15:316-323 (1988)). Although these infections stimulate both specific T and B cell-mediated (Ebersole, J. L., et al., J. Periodont. Res. 22:184-186 (1987); Stashenko, P., et al., J. Periodont. Res. 18:587-600 (1983)) and non-specific (neutrophils, monocytes and cytokines) host responses, most data support a key role for the non-specific arm, in particular neutrophils and other phagocytic cells, in host defense against these microorganisms (Genco, R. J., J. Periodontol. 63:338-355 (1992); Van Dyke, T. E., and G. A. Hoop, Crit. Rev. Oral Biol. Med. 1:117-133 (1990)). This is illustrated by findings that individuals with neutrophil defects, including chronic granulomatous disease, cyclic neutropenia, Papillon-Lefevre syndrome, leukocyte adhesion deficiencies, and Chediak-Higashi syndrome exhibit dramatically increased incidence and severity of periodontal destruction (Barrett, A. P., et al., Oral Surg. Oral Med. Oral Path. 69:174-176 (1990); Bauer, W. H., J. Dent. Res. 25:501-508 (1946); Cohen, M. B., et al., J. Periodontol. 56:611-617 (1985); Cohen, D. W., and A. L. Morris, J. Periodontol. 32:159-168 (1961); Tempel, T. T., et al., J. Periodont. Res. 7 (Suppl 10):26-27 (1972); Van Dyke, T. E., et al., Clin. Immunol. Immunopathol. 31P:419-429 (1984)).
Current treatments for human periodontal disease focus on debridement and surgery to reduce the microbial load and enhance the ability of the patient to maintain infected sites. Because periodontal disease is now recognized as an infection by a limited spectrum of pathogens, adjunctive antimicrobials are also coming into wider usage (Slots, J., and T. E. Rams, J. Clin. Periodontol. 17:479-493 (1990)). A great need remains for safe and effective treatments for periodontal disease.